A wide variety of portable electronic devices may be equipped with displays which provide dimensional information. Such stereoscopic imaging provides the illusion of depth to the user. This has a variety of applications in interfaces used for control operations and/or for entertainment purposes. For illustration, modern mobile telephones or personal digital assistants may be equipped with stereoscopic displays.
Autostereoscopic displays which do not require the user to wear specifically designed glasses for providing different images to the left and right eye are particularly attractive with regard to user convenience. Such autostereoscopic displays have a display panel which outputs plural images, and an optical device which directs one of the images to one eye and another one of the images to another eye of the user.
Conventionally, autostereoscopic displays have required the user to remain at a pre-defined position relative to the autostereoscopic display for obtaining good three-dimensional viewing experience. One approach to further enhance convenience for the user is based on using a multi-view configuration in which different perspective images are generated and displayed in various angular zones. This approach is computationally costly, as the constituent images of more than one perspective view must be computed even when there is only one user present in front of the display. Another approach to enhance convenience for the user is based on using an optical device overlaid on the display panel. The optical device can be controlled based on a direction in which the user is positioned relative to the autostereoscopic display.
While stereoscopic imaging can be implemented by generating only two images that are directed to the user's left and right eye, respectively, when a control of the optical device based on the direction in which the user is positioned is used, this still imposes limitations on the relative positions between the user and the autostereoscopic display where good depth illusion is provided by the autostereoscopic display.